Ecology and Evolutionary Biology Commons^™

Center For Grassland Studies, May 2021

Center for Grassland Studies: Newsletters

Contents

Prescribed Burn Associations by Brian Teeter

Center for Grassland Studies Policy Advisory Committee

Director's Column by Walt Schact (Interim Director)

Looking for a Career in Conservation – How to Apply in USAJOBS for NRCS Positions by Mary Reece

Monitoring Sandhills Rangelands: A Key Step in Understanding Plant Community Dynamics by Mitch Stephenson

Development of Novel Plant Fluorescence Based Techniques for Remote Assessment of Grasslands and Pastures Health and Resilience by Anastasios Mazis

UNL PGA Golf Management Alumni Among Nebraska Section Award Winners by Brad Goetsch

Nebraska’s Grassland Legacy by Walt Schacht

Nebraska Grazing Conference: Save the Date, August 9-11, …

Social Partners And Temperature Jointly Affect Morning Foraging Activity Of Small Birds In Winter, Anastasia E. Madsen, Laura N. Vander Meiden, Daizaburo Shizuka

Papers in Behavior in Biological Sciences

Daily foraging activity of small wintering birds is classically thought to be driven by the need to gather enough energy reserves to survive each night. A separate line of research has shown that sociality is a major driver in winter foraging activities in many species. Here, we used wintering birds as a study system to move toward an integrative understanding of the influence of energy requirements and sociality on foraging ecology. We used RFID-enabled feeders in Lincoln, Nebraska, USA in January–March 2019 to measure foraging activity in two species (downy woodpeckers, Dryobates pubescens, and white-breasted nuthatches, Sitta carolinensis). …

Environmental Racism In A Growing City: Investigating Demographic Shifts In Salt Lake City's Polluted Neighborhoods, Emma Nathel Jones

Undergraduate Honors Capstone Projects

Studies investigating the spatial distribution of environmental hazards have repeatedly demonstrated the existence of environmental racism -- the disproportionate impact of environmental hazards on communities of color. We aim to contribute to research on environmental racism by asking how relationships between race and hazard exposure change over time. Our study area, Salt Lake City (SLC), UT, USA is one of the largest cities in the intermountain west and is expected to see continued population growth. SLC was 99% white from 1860-1950. 2019 census estimates indicate that SLC is becoming more racially diverse with 35.6% of the population identifying as racial …

Saving Butterflies In The City: Gardens As Conservation Spaces In Urban Landscapes., Lindsay D. Nason

Electronic Theses and Dissertations

Butterfly populations are declining, and habitat degradation due to urbanization is a major contributing factor. Gardens represent a large proportion of land area in many cities, and thus may be important for conserving butterflies in urban environments. In this dissertation, I examine how garden features (ex: size, level of urbanization, plant diversity) affect adult butterfly diversity/abundance, behavior, and the predation risk faced by caterpillars. My study sites were native plant gardens in Jefferson, Bullitt, and Hardin Cos.,KY. In Chapter One, I used clay caterpillars to assess differences in predation pressure in gardens along a gradient of percent impervious surface (%IS). …

Distribution And Ecological Effects Of Azteca Chartifex/Trigona In The Barro Colorado Nature Monument., Rachel Leann Wells

Electronic Theses and Dissertations

This dissertation explores the behavior and ecology of a conspicuous and behaviorally dominant ant species in the tropical rainforest of Panama. Competition with aggressive species is an important factor that shapes local community structure. Eavesdropping on the chemical communication systems of such behaviorally dominant species can help heterospecific species to avoid negative interactions. I review the chemical communication system and known ecological effects of the Neotropical canopy ant, Azteca chartifex/trigona (Chapter 1). There are over 40 known compounds produced by Azteca workers, yet how these compounds impact heterospecific species is unclear in many circumstances. I assessed if heterospecific …

Bighorn Sheep Demographics Following Pneumonia Die-Off Events, Kylie Sinclair

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bighorn sheep populations across the Intermountain West are subject to disease pressure from the respiratory bacteria Mycoplasma ovipneumoniae. Although the effects of M. ovipneumoniae-associated disease die-offs are well documented, less is known about the factors driving long-term differences in post-die-off population responses. While many herds experience years to decades in which recruitment is less than 20 lambs per 100 ewes, some herds’ lamb survival rates are able to rebound rapidly following die-off events. The reason why these herds recover quickly while others do not is currently unknown. Here, we assess the roles environmental, demographic, and pathogen-associated factors could …

Range-Wide Migratory Connectivity Of Painted Buntings, Andrew J. Sharp

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Painted Bunting (Passerina cirus) is a small (~16g), short/medium-distance migratory songbird that is listed as a species of conservation concern by the US Fish and Wildlife Service. Painted Buntings breed in two distinct populations, one eastern population and one interior population, separated by a 500 km gap that stretches from Mississippi to Georgia. I analyzed tracking data from 112 Painted Buntings from 11 different breeding sites to explore how individuals from different breeding sites differ in wintering location (chapter 2) and migratory timing (chapter 3). Additionally, I examined differences in migratory behavior between male and females in …

Greater Sage-Grouse And Community Responses To Strategies To Mitigate Environmental Resistance In An Anthropogenic Altered Sagebrush Landscape, Justin R. Small

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sagebrush (Artemisia spp.) ecosystems are diverse habitats found throughout western North America. Anthropogenic disturbances has resulted in the loss of over half of the sagebrush ecosystems impacting sagebrush obligate species such as sage-grouse (Centrocercus spp.). Federal, state, and private land managers have implemented landscape scale mechanical pinyon (Pinus spp.) and juniper (Juniperus spp.; conifer) removal projects in an effort to restore functioning sagebrush communities to benefit sage-grouse. However, few studies have investigated the potential for using large-scale conifer treatments to mitigate factors impeding sage-grouse seasonal movements and space-use in anthropogenic altered landscapes.

To address this management need, I …

Patterns Of Post-Fire Aspen Seedling Establishment, Growth, And Mortality In The Western United States, Mark Regier Kreider

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sexual seedling establishment in aspen is increasingly recognized as an important natural regeneration pathway for the species in the western U.S. However, information on seedling abundance as well as factors influencing aspen sexual regeneration is limited and frequently anecdotal, due to historical assumptions of seedling rarity as well as difficulty identifying sexual seedlings from asexual aspen sucker regeneration. This thesis contributes to the field of aspen seedling ecology in three major ways. Chapter 1 utilizes historical aspen seedling occurrences in the western U.S. and a systematic field survey of 2018 fire footprints to explore patterns and test assumptions of aspen …

Mechanisms Of Overyielding And Coexistence In Diverse Tallgrass Prairie Communities, Leslie E. Forero

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plants compete for the same basic nutrient and water resources. According to the competitive exclusion principle, when a substantial overlap in resource pools exists, the best competitor for resources should drive all other species to extinction. The ability for plants to coexist in violation of the competitive exclusion principle is the “biodiversity paradox”. Coexistence is actually beneficial for plants: as species diversity increases, you typically see increases in plant biomass production (known as the biodiversity-productivity relationship). The mechanisms behind coexistence and the biodiversity-productivity relationship remain an ecological mystery. One hypothesis is that plants obtain water and nutrients from different places …

The Fate And Cycling Of Nitrogen, Phosphorous, And Trace Heavy Metals In Beaver-Altered Headwater Streams, Desneiges S. Murray

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Human land-use can increase the amount of non-point source (NPS) pollution in a stream, negatively affecting ecosystem health and beneficial services provided by an ecosystem. Unfortunately, NPS pollution remains high in many waterbodies. Beaver dams may be a passive, cost-effective strategy for removing NPS pollution in headwater streams because beaver dams slow stream flow and collect sediments. Impounded sediments can change how nutrients and pollutants are cycled in a stream through multiple pathways. In the first part of our study, we investigated whether beaver activity can reduce nitrogen, phosphorous and heavy metals from otherwise traveling downstream. Results suggest beaver ponds …

Trends In Us Crop Yields & Water Use, Britta L. Schumacher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Over half the land in the US is dedicated to agriculture, with the vast majority of all cropland cultivated in corn, wheat, or soybean. Despite continuing advances in agricultural technologies, and consistent yield growth over the twentieth century, research suggests that environmental change is already impacting agricultural yield and future changes are sure to exacerbate challenges to agricultural production. It follows that the future of US agriculture depends on the evolution of the changing climate, the relationship between crop yields and the environment, on-farm management and adaptations, the ecosystems that support agriculture, the political and economic incentives that shape what …

Short- And Long-Term Mechanisms For Increasing Inputs Of Phosphorus In Mountain Waterbodies Of Northeastern Utah, Usa, Jessica Scholz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Phosphorus is an essential nutrient that allows life in water to flourish, but changes in phosphorus supplies are not well understood in remote watersheds. In mountain environments, remote watersheds contain critical high-quality water supplies and unique ecosystems, but excess phosphorus can diminish water quality by producing unfavorable aquatic species. Therefore, observed trends of increasing phosphorus concentrations in remote lakes and rivers in the US over the last two decades are a significant concern. Using the Uinta Mountains as a case study, we evaluated three different direct and indirect pathways for phosphorus increases in remote mountain watersheds that may explain observed …

Invasive Plant Occurrence Across Agency Boundaries: Two Case Studies From California, Natalie Otto

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Non-native invasive species (NNIS) are a major concern confronting land managers in and surrounding protected areas such as national parks. These areas are managed by a variety of entities, all of which have different mandates, management priorities, and resources that are allocated to NNIS programs. These differences can result in ecological divergences at land boundaries and can create barriers to cooperative management. Through interviews and ecological data collection, this research addresses three topics; 1. It identifies disparities in NNIS and disturbance occurrence between jurisdictions and tests the strength of correlations between these variables; 2. It seeks to determine what role …

Responses Of Pacific Fishers To Habitat Changes As A Result Of Forestry Practices In Southwestern Oregon, Tessa R. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The fisher (Pekania pennanti) is a medium-sized carnivore found in mature forest stands across much of the northern United States. Although historically abundant in the west, fisher populations declined rapidly after fur trapping, extensive logging, and urban development reduced their numbers. Currently, biologists are concerned about the effects timber harvest practices have on fisher tolerance and adaptability when faced with changes to high-quality habitat stands. Tree removal and thinning of understory vegetation are frequently used to alleviate the spread of wildfires in previously dense forest stands with a potential for large-scale habitat loss; yet, a deficit of large …

Monitoring Populations And Movement Of Bobcats (Lynx Rufus) On The Eastern Slope Of The Sierra Nevada Mountains Of California, Michael Brown

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Monitoring the spatial ecology and population densities of carnivores is critical for effective management and conservation of these populations and the ecosystems in which they exist. However, effective monitoring of carnivore populations through estimates of space use, habitat selection and densities can be difficult due to their relatively low densities and wide ranging, elusive behaviors. Bobcats (Lynx rufus) are medium sized, top-level predators which are widely distributed across North America. Quantifying space use, habitat selection and developing effective population monitoring strategies for this species will have important implications for wildlife management.

My first objective was to use telemetry …

The Phylogeography And Molecular Systematics Of Woodrats (Genus: Neotoma) In The American Southwest, Katrina M. Derieg

Biology ETDs

The American Southwest is a region where many biomes converge, harboring a wide variety of habitats ranging from desert to alpine environments. Habitat heterogeneity and the confluence of multiple species ranges make the American Southwest a biodiversity hotspot. Climate cycling throughout the Quaternary has driven the dynamics of changes in species’ ranges that are recorded by genetic signatures. For example, range expansion may lead to secondary contact between previously isolated populations or species. Contact can result in multiple evolutionary outcomes, including hybridization or the reinforcement and maintenance of independent lineages. I used multi-locus species tree methods to re-examine the nominal …

Climatic Controls Of Plant Productivity, Phenology, And Physiology In Drylands, Alesia Jane Hallmark, Scott L. Collins, Marcy E. Litvak, Christopher D. Lippitt, Andrew D. Richardson

Biology ETDs

Drylands play a critical role in global carbon dynamics. Anthropogenic climate change is causing these hot and dry regions to become increasingly hotter, drier, and more variable. This is especially concerning as drylands are some of the most sensitive regions to changes in aridity. It is critical to understand how dryland plant species might react to a changing climate. In this dissertation, I explored the relative effects of plant community composition and dominant species abundance on determining ecosystem-wide carbon dynamics. I compared the population stability of 98 dryland plant species and related stability to phenological traits. Lastly, I related branch …

Resistance Of The Freshwater Microbiome To A Combination Of Pesticides, Gabriel Hooper

Senior Honors Theses

Pesticides are used prevalently throughout the United States and can negatively affect non-target organisms. Rain run-off can move multiple pesticides into freshwater ecosystems and bring them in contact with non-target organisms that have variable tolerances to pollution. This study seeks to improve our understanding of how an acute exposure to a combination of pesticides may restructure microbial communities by examining the microbiome before and after a 48-hour exposure to 2000 ppb of herbicides (glyphosate, atrazine, and 2,4-D). Pesticide exposure did not significantly alter the alpha or beta diversity of the sample types, which demonstrates the ability of freshwater microbiomes to …

Pando's Lessons: Restoration Of A Giant Aspen Clone, Paul C. Rogers, Jody Gale, Darren Mcavoy

Aspen Bibliography

A 106 acre (43 ha) aspen clone lives in the Fishlake National Forest in south-central Utah. Clones are comprised of multiple aspen stems, called ramets, which are genetically identical. This particular colony of ramets was named “Pando” (Latin for “I spread”) by researchers believing it to be the largest living organism by mass on earth. Recently, forest managers have noted a rapid dying of mature stems without recruitment of younger trees. This unsustainable situation has galvanized restoration efforts at Pando. Human interventions caused this imbalance; restoration will rely on protection, monitoring, and innovation. As a laboratory, this forest icon may …

Sublethal Effects Of Red Imported Fire Ant Envenomation On Hatchlings Of North American Oviparous Snakes, Hannah Warner, Meredith Swartwout

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Invasive species cause major ecological and economic damage. The Red Imported Fire Ant (RIFA; Solenopsis invicta) has successfully invaded much of the southeastern United States and has caused both widespread economic damage and is suspected to be the driver of enigmatic declines of several oviparous snake species. This study aimed to determine the sublethal effects of RIFA on hatchlings of six species of oviparous snakes (Coluber constrictor, Lampropeltis calligaster, L. holbrooki, Opheodrys aestivus, Pantherophis emoryi, and P. obsoletus) by exposing hatchlings to envenomation by RIFA and then measuring two performance metrics: righting response and …

Contaminated Mycoscapes: Designing With Living Organisms, Maria Gutierrez, Elise Zilius

Architecture Senior Theses

The Anthropocene has stripped the planet of its resources, leaving behind an abundance of contamination. The built environment no longer meets the standards set by our turbulent planet. Humankind has lost the privilege of agency in design and construction. Construction methods have failed to evolve concurrently to the intense accumulation of waste; remaining firmly rooted in the materiality of the past, they have upheld architectural notions of stagnancy, cleanliness, and hygiene and ignore the rapidly changing conditions of the environment. This investigation uses contamination to fuel mycelial growth and construct emergent forms whilst executing remediation strategies for polluted sites of …

How Wildlife Respond To Natural Noise, Dylan G. E. Gomes

Boise State University Theses and Dissertations

Animal sensory systems have evolved in a natural din of noise since the evolution of sensory organs. Anthropogenic noise is a recent addition to the environment, which has had demonstrable, largely negative, effects on wildlife. Yet, we know relatively little about how animals respond to natural sources of noise, which can differ substantially in acoustic characteristics from human-caused noise. Here we review the noise literature and suggest an evolutionary approach for framing the study of novel, anthropogenic sources of noise. We also push for a more quantitative approach to acoustic ecology research.

To build a better foundation around the effects …

Analysis Of The White-Tailed Deer Population Of Hobbs State Park, Jesse Morrison

Biological and Agricultural Engineering Undergraduate Honors Theses

White Tailed deer (Odocoileus virginianus) are the only deer species native to Arkansas, playing a crucial role in the ecosystem. Healthy deer populations are important for environmental and human wellbeing, and overpopulation can lead to poor herd health, overgrazing, increased vehicle collisions, and transmission of diseases. Monitoring deer populations through surveys can be a useful tool in managing wildlife and maintaining Arkansas’ natural resources.

This study analyzed trends in Hobbs State Park’s deer population and estimated the current roadside deer population of the park. Data from past surveys was analyzed for trends using a Mann-Kendall Test, and a distance sampling …

Natural Noise Can Influence Bird Foraging And Vigilance Behavior, Kate Antonia Sweet

Boise State University Theses and Dissertations

Natural sounds are an often overlooked, yet important component of an animal’s habitat. The acoustic environment may be especially significant during foraging, because a noisy world can limit auditory surveillance. Here, we investigated how natural noise structures the foraging vigilance trade-off to understand how intense acoustic environments may have shaped antipredator behavior across the evolutionary past, and better inform conservation efforts in the present.

First, in Chapter 1, I directly compared the foraging and vigilance behaviors of captive song sparrows (Melospiza melodia) in anthropogenic and natural noise. We recorded foraging trials in 4 playback conditions (roadway traffic, whitewater …

Gray Wolves, Eric Gese, John P. Hart, Patricia Terletzky

Wildlife Damage Management Technical Series

Wolf conflicts are primarily related to predation on livestock, pets and other domestic animals, as well as their direct and indirect impacts on native ungulates (i.e., big game). Economic losses vary widely with some livestock producers facing high levels of depredation in some areas. This publication focuses on wolf ecology, damage, and management, particularly as it relates to wolf depredation on livestock and other conflicts with people.

Wolves and people share the same environments more than people realize. In the U.S., wolves are not confined to wilderness areas. Though curious, wolves generally fear people and rarely pose a threat to …

Ecology And Vegetation In A Passively Managed Urban Park In Worcester, Ma, Raphaella Mascia

College Honors Program

As urbanization continues to expand globally, urban parks are becoming critical habitats for human and non-human species alike. Understanding the various contexts and conditions of local parks prompts improved management and conservation efforts for such expanding urban habitats. Therefore, I assess the ecology and vegetation of a local park, Cookson Field, located in Worcester, MA, US, through a comprehensive series of vegetation surveys and examine its urban context through an examination of land-use history. I find that Cookson Field is primarily an oak (Quercus sp.) woodland with an ericaceous understory consisting mainly of blueberry (Vaccinium sp.) …

Particle Tracking Reveals Pelagic Red Crabs As Indicators Of Climate-Driven Range Expansion In The California Current, Elizabeth Saraf

Senior Honors Projects

Since their first recorded occurrence in 1859, Pelagic Red Crabs (PRC; Pleuroncodes planipes) have experienced increased frequency of episodic mass stranding events in the Eastern Pacific Ocean. PRC’s are transported over 1,000 km northward of their central domain from the coast of central Baja California, Mexico. They have been reported by the thousands on the beaches of central and southern California. Their presence influences the surrounding ecosystem and commercial fisheries because they are nutritional prey items and large predators change their diet to incorporate PRC’s when they are available. Seasonal coastal currents and the California Undercurrent transport warmer waters …

Synthetic Viral Pyrogen Induces Behavioral Fever In Plethodon Glutinosus Salamanders, Nicholas Britt

Undergraduate Honors Theses

Behavioral fever is an essential coping mechanism across ectothermic phyla to aid in combating pathogenic threats. Ectotherms lack internal temperature regulation associated with fever in endotherms; thus, ectotherms can exhibit a behavioral fever response when immunocompromised to thermoregulate by moving to warmer locations. The salamander order Caudata, tend to be keystone species in their resident ecosystems through their role as secondary consumers of invertebrates to maintain the food chain. With growing interest about ecology and conservation of salamanders as species diversity declines, this study was designed to determine if salamanders use their environment to take advantage of behavioral fever. The …

Troglofauna Of Van Buren And White County: A Survey Of Four Caves In The Mideastern Cumberland Plateau, Gavin Page

Honors Theses

The Cumberland Plateau in Tennessee has the highest cave-obligate biodiversity in North America. Cave-obligate species are entirely restricted to subterranean habitat and demonstrate unique troglomorphy. These species are categorized as troglobionts. However, because of their isolated occurrences, theses species are vulnerable to a variety of disturbances. This issue is furthered in the fact that only approximately 7% of the caves in this region have been surveyed. Of these caves that have been surveyed, only a small portion were professional entomological surveys, while almost no cave has ever been extensively repeat sampled. This study involved newly sampling one cave and repeat …